Energy savings added up in April

When the pandemic closed campus in March, the university implemented energy-saving measures similar to those taken during a winter break partial shutdown in buildings with low or no occupancy. Mark Kruse, utilities services director in facilities planning and management (FPM), said 66 buildings -- nearly half of Iowa State's campus inventory -- implemented some energy reduction measures, saving more than a half million dollars in utilities costs in April alone.

"The energy management staff in FPM deserves all the credit, quickly developing and implementing a plan to lower building temperature set-points, extend set-point time duration and turn off lights," Kruse said.

Iowa State uses multiple energy sources:

  • Chilled water (used for cooling buildings, walk-in coolers and IT equipment)
  • Electricity
  • Steam (used for heating buildings and hot water, humidification and sterilization equipment)
  • Natural gas
  • Water/sewer

In comparing this April's energy consumption with average use over the last four years, every energy source saw a double-digit percentage drop, in part helped by mild weather conditions. The nearly 11% decrease in steam use seems modest compared to a 73.2% drop in water and sewer demand. But it was the 27.5% non-weather-related electricity reduction that saved $270,136 -- the biggest chunk of the $586,340 total cost reduction.

"These are the lowest campus energy flows we've seen in about 20 years," Kruse said.

Kruse said there was little change in energy use in research buildings and labs, while residence halls and the Iowa State Center saw the biggest reductions. 

Although many buildings were closed, they were not abandoned. Kruse said FPM staff maintained water quality by testing and flushing the lines weekly, which they continue to do. He said FPM brought building environmental controls back to "normal" operations as part of the phased reopening plan.

"FPM wants to make sure the buildings are ready and safe for use when people return to campus," Kruse said.


April energy consumption

Utility April avg (2016-19) 2020 use % decrease Cost reduction
Chilled water 2,201,818 tons 1,226,212 44.3% $202,633
Electricity 12,727,897 kilowatt-hours 9,222,234 27.5% $270,136
Steam 49,119,051 kilowatt-hours 43,750,032 10.9% $78,869
Water/sewer 18,409,502 gallons 4,929,063 73.2% $27,120
Gas 9,005,819 cubic feet 7,751,680 13.9% $7,581